Vulnerability Discussion

It is important to disable any unnecessary components to reduce any potential attack surfaces.

RKE2 allows disabling the following components:
- rke2-canal
- rke2-coredns
- rke2-ingress-nginx
- rke2-kube-proxy
- rke2-metrics-server

If utilizing any of these components presents a security risk, or if any of the components are not required then they can be disabled by using the "disable" flag.

If any of the components are not required, they can be disabled by using the "disable" flag.

Satisfies: SRG-APP-000141-CTR-000315, SRG-APP-000384-CTR-000915

Check

Ensure the RKE2 Server configuration file on all RKE2 Server hosts contains a "disable" flag only if there are default RKE2 components that need to be disabled.

If there are no default components that need to be disabled, this is not a finding.

Run this command on the RKE2 Control Plane:
cat /etc/rancher/rke2/config.yaml

RKE2 allows disabling the following components. If any of the components are not required, they can be disabled:
- rke2-canal
- rke2-coredns
- rke2-ingress-nginx
- rke2-kube-proxy
- rke2-metrics-server

If services not in use are enabled, this is a finding.

Fix

Disable unnecessary RKE2 components.

Edit the RKE2 Server configuration file on all RKE2 Server hosts, located at /etc/rancher/rke2/config.yaml, so that it contains a "disable" flag if any default RKE2 components are unnecessary.

Example:
disable: rke2-canal
disable: rke2-coredns
disable: rke2-ingress-nginx
disable: rke2-kube-proxy
disable: rke2-metrics-server

Once the configuration file is updated, restart the RKE2 Server. Run the command:
systemctl restart rke2-server